The present invention generally relates to holding devices and more specifically to devices for holding parts during the movement of the parts to an installing device.
Holding devices are commonly used in manufacturing operations to hold parts as they are being moved from a parts feeder to a parts installing device. For example, during the manufacture of internal combustion engines, valve guide inserts are moved from a valve guide feeder to a press unit that inserts or presses the valve guide inserts into valve guide bores of a cylinder head. An automated delivery system is typically provided for moving the valve guide inserts from the valve guide feeder to the press unit. An example of such an automated delivery system is disclosed in U.S. Pat. No. 4,832,176 to Okuma et al., which is assigned to the assignee of the present invention and is hereby incorporated by reference. In the Okuma et al. patent, the delivery system includes a parts supplying device that moves valve guide inserts from a parts distributing device to a parts installing device (press). The parts supply device includes a holder for holding the valve guide inserts as they are being moved from the parts distributing device to the press.
The holder of the Okuma et al. patent includes a plurality of holes for receiving the valve guide inserts. A plurality of other holes or bores are disposed perpendicular to the receiving holes and are in communication with radially outer portions of the receiving holes. Spring-biased lock pins are disposed in the bores and are movable between holding and release positions. When valve guide inserts from the parts distributing device are deposited in the receiving holes of the holder, the lock pins are located in their release positions and do not obstruct the movement of the valve guide inserts into the receiving holes. When the holder moves away from the parts distributing device, a cam member moves the lock pins to their holding positions, which causes the lock pins to engage the valve guide inserts, thereby preventing the valve guide inserts from moving or falling out of the receiving holes. When the holder arrives at the parts installing device, the cam member moves the lock pins back to their release positions, which causes the lock pins to disengage from the valve guide inserts, thereby permitting the valve guide inserts to be transferred to the press.
It has been observed that after a period of use, parts holders having a construction similar to the holder of the Okuma et al. patent will, on occasion, malfunction and drop the parts they are holding. Such malfunctioning can be attributed to the accumulation of debris (such as metal particles from the parts) in the receiving holes and bores of the holders. This accumulation of debris interferes with the operation of the locking pins and prevents them from properly holding the parts in the receiving holes.
Based on the foregoing, there is a need in the art for a holding device for holding parts, such as valve guide inserts, during the movement of the parts to an installing device, such as a press unit, wherein the holding device is not susceptible to malfunctioning due to the accumulation of debris. The present invention is directed to such a holding device and to a supply system utilizing such a holding device, as well as to a method of moving parts.